Three charts that show how MPs could vote on Brexit deal
The House of Commons will sit on a Saturday tomorrow for the first time since the Falklands War, as MPs face a crunch vote on whether to back Boris Johnson’s Brexit deal.
The Prime Minister may have got the deal past European Commission president Jean Claude Juncker, but his support in Parliament is on a knife edge.
Read more: Three key changes that underpin the new Brexit deal
We have 650 MPs in the House of Commons, but only 639 of them vote. That means Johnson needs 320 MPs to vote for his deal to be sure of a majority.
However, the DUP, which props up the Tory government with its 10 MPs, has already refused to back the deal, meaning the PM needs to look elsewhere for support.
So who are the key groups he has to win over?
The European Research Group
There are 287 Conservative MPs, and all will be told by party whips to vote for the deal. But most important within this group is the ERG, or self-styled Spartans.
This group of 28 Tories voted down Theresa May’s deal on all three occasions, and support a hard Brexit.
Some already appear supportive of the deal, including the influential Jacob Rees Mogg – although that may be because he is now part of Johnson’s cabinet.
Others are still on the fence. Well-known hardliner Mark Francois appears unconvinced, having told broadcasters earlier today he still has “some concerns about some of the specifics of the deal”.
Meanwhile, head of the ERG Steve Baker is refusing to give anything away until tomorrow…
Significantly for Johnson, however, he has found more favour with the group than his predecessor managed to.
If he wins all of their support, as well as all the other Tories, he needs to find 33 more MPs…
FOR 287 – 352 AGAINST
Read more: Emmanuel Macron says he will veto Brexit delay
Former Conservatives
Johnson took away the whip from 21 of his own MPs last month for voting to block a no-deal Brexit. That number rose to 22 when former Home Secretary Amber Rudd quit the party.
Six of them – Richard Benyon, Greg Clark, Stephen Hammond, Richard Harrington, Sir Oliver Letwin and Sir Nicholas Soames – have already indicated they are planning to vote for the deal.
Soames told BBC Newsnight: “My quarrel with the Prime Minister was over nothing except for no-deal. So there is a deal, and I will vote for it and so will many of my colleagues who had the whip taken away from them.”
He also indicated the rest of the group was likely to back the deal. He added: “It’s not a great deal, this isn’t a great deal, but it’s not a bad deal. I think you can assume that the 21 will by and large vote for it.”
Rudd, meanwhile, has yet to commit.
But assuming he wins over this grouping, The PM needs just 11 more votes…
FOR 309 – 330 AGAINST
Read more: Brits prefer Boris Johnson’s Brexit deal to another delay ahead of crunch MPs’ vote
Labour rebels
Labour leader Jeremy Corbyn and shadow chancellor John McDonnell have made it very clear the party does not support the deal. But some feel this is their chance to save the UK from a no-deal Brexit.
Sarah Champion, Labour MP for Rotherham, has already told one of her constituents she will back the deal, according to Buzzfeed.
Ronnie Campbell, Labour MP for Blythe who is pro-leave, has also told ITV he will back the deal. He said: “I’m not supporting Boris Johnson, I’m trying to support getting the deal through parliament.”
Jim Fitzpatrick and Kevin Barron have also suggested they could back it.
A total of five Labour MPs backed Theresa May’s deal, but some estimates have it that as many as 20 could back this one, with a number of party members’ constituencies having voted overwhelmingly to leave the EU in 2016.
If that happens, the deal might make it over the line.
FOR 329 – 310 AGAINST
Read more: Bank of England deputy suggests Brexit deal could see rates rise
But this is by no means certain.
Most commentators estimate that Johnson will lose at least a handful of supporters from each of those groups, meaning the final result could come down to just one or two votes.